Electrical apparatus



Jufie 1 1926.

E. M. HQNAN ELECTRICAL APPARATUS Filed June 27, 192].

75 Cow malady Patented June l, 1923.

UNi'rr. a

EDWARD ll/I. HOIJAN, OF EAST ORANGE, NEW JERSEY, ASSIGITGR T0 WESTERN ELEC- TRIG GGMPANY, INCORPORATED, OF NEVT YORK, N. L, A GGR'EORATION 05 NEW YORK. ELECTRICAL Application filed June 27,

This invention relates to electrical apparatus and particularly to methods of pro tecting the physical and electrical properties thereof.

In protecting electrical apparatus from moisture, temperature and other influences having a detrimental eficct thereon, it is common practice to treat the parts to be protected with a covering material, usually an organic compound, which serves to prevent the ingress of damaging elements. lhe usual method of applying protective material to electrical apparatus is to immerse the parts in a molten compound and subsequently assemble the treated parts, or immerse the completed structure in the compound, a tedious and expensive process which involves considerable time during which the apparatus is immersed in the impregnating tanks. Further, it is frequently desirable to employ compounds such as certain of the pitches and asphalts, having relati ely high melting points in order to completely drive out the moisture and to prevent flowing out under the heat developed by the operation of the apparatus when in service. In such cases the insulating material used in the electrical apparatus, such as paper, cotton, silk, or the like, may be subjected to serious injury by directimmersion in the molten bath. Although it is impossible to determine the exact temperatures at which these insulating materials are adversely affected, it has been found injurious to subject any of them to a temperature over about 300F. for any considerable length oi time. The use of a solvent as a vehicle for impregnating compounds havinghigh meltpoints has undesirable features when the usual impregnation under vacuum is employed because the rapid evaporation of the solvent alters the viscosity of the solution.

t is an object of this invention to provide a method of applying protective material to electrical apparatus whereby high melting point materials, either molten or in solution, may be employed.

In accordance with its object the invention contemplates applying a protective ma terial to electrical apparatus during the construction of the same, this being accomplish'ed by applying the material in a fluid condition by some mechanical means such as brushing, spraying or by extruding the material in filament form. It has been found APPARATUS.

1321. Serial No. 480,897.

that by introducing the protective material in this manner so that the mass of heated compound introduced at any time is quite small, the heat communicated to the contig uous insulation is so small that little or no bad effects result therefrom. It has also been found that the application of the mois tine-proofing material to the apparatus during its assembly insures more complete and thorough impregnation than where the apparatus is first constructed and then subjected to the moisture-proofing material. For instance, the use of this improved method in the impregnation of electrical coils while they are being wound, provides a greater certainty that the moisture-proofing material will completely penetrate to interstices within the coil near the core, than where the coil is impregnated after its assembly. Furthermore, the method herein disclosed pei the introduction of moisture-proofing material into the coil without spreading it over the spool-heads, pole pieces and other parts oi the coil where it is not desired. As a consequence the necessity of the trouhleson'ie cleaning of the apparatus after the completion of the impregnation, is obviated. These advantages are present in the use of this method in impregnating any electrical apparatus since the moistureprooiing material may be applied only to those parts of the apparatus where impregnation is desired without subjecting the entire apparatus to the moisture-proofing material.

The following description and the accompanying drawing relate to one possible application of this invention, namely, that of applying moisture-prooiing material to electrical coils, but the invent-ion is also applicable to applying materials for this and other purposes to othcr electrical apparatus, such as insulated wires, condensers, resistance, units, etc., and it is not intended to limit the invention except within the scope of the appended claim.

The drawing shows a method of automatically applying moisture-proofing material to a coil in the form 01 a spray, only so much of the autoinaiic system being shown as necessary to a complete understanding of the invention.

Referring to the drawing, 1 represents a rotatable spindle adapted to receive a spool or core 2 uponwhich the coil is to be wound.

X spool 73, supporting the insulated wire l,

is mounted in any convenient manner so as to permit the wire to be freely withdrawn therefrom upon the application of tension er-zerted thereon by the rotation of the spindle 1. A mounting frame 5 acts as a support for the shaft (5 upon which is mounted the plate T, carrying the nozzle 8, and ada to more slidahly along the said shaft in close proximity to the spool 52. A wormed shaft 9 is rotatably mounted on the mounting frame 5, the threads of this shaft being in engagement with corresponding threads in the plate 7. It will be seen that the rotation of the shaft 9 will cause the movement of the nozzle 8 along the stationany sha ft (3 and longitudinally adjacent the spool The movement of the shafts 1 and 9 are synchronized in any suitable manner, as by driving the two shafts from the same power source, not shown in the drawing, so that the nozzle 8 will always be adjacent the point where the wire is being applied to the coil. As shown in the drawing, the moistureprooling compound is fed to the nozzle through a tube 10, and is forced out upon the coil in the form of a fine spray by intermixing with a gas under pressure which is fed to the nozzle through a separate tube 11 and which mixes with the impregnating coinpound within the nozzle, forcing out the compound in a linel divided state. Any suitable gas may be employed such, for e):- aniple, as air. It will be understood, of course, that other means may be cn'iplo ved for applying the material to the coil, such as brushing or extruding the material in lilanient form, as stated above. It will be ohvious that by the use of this invention, corn pounds having extremely high points may be used as a nioisture-prooiing material for electrical apparatus, the amount of heat being coini'nunicated at any time being so small as to minimize the bad effects resulting tnerefroin.

XV hat is claimed is:

The method of constructing electrical coils which consists in rotating a core about its longitudinal axis, feeding an insulated conductive wire thereto to be wound thereon by the rotation of the core, and constantly inipregnating that portion of the insulating covering which is being wrapped upon the coil with moistinieprooting material in the form of a fine spray so that only a sn'iall portion of the material is applied at one time.

In witness whereof, I hereunto subscribe my name this 23rd day of June, A. 11). 192i.

EDXVARD M. I l-BIKE.

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